Patents by Inventor Hwai Choo

Hwai Choo has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20060082296
    Abstract: A device and method for emitting output light of a desired color utilizes green-emitting Thiogallate phosphor material and red-emitting SrCaS:Eu phosphor material to convert some of the original light emitted from a light source of the device to a longer wavelength light in order to produce the desired output light. The green-emitting Thiogallate phosphor material includes at least one of CaGa2S4:Ce phosphor and BaGa4S7:Eu phosphor. The device and method can be used to produce white light or other mixed color light using the light source, which may be a blue-green light emitting diode (LED) die.
    Type: Application
    Filed: October 14, 2004
    Publication date: April 20, 2006
    Inventors: Janet Bee Chua, Hisham Menkara, Christopher Summers, Azlida Ahmad, Hwai Choo
  • Publication number: 20050167684
    Abstract: A device and method for emitting output light utilizes Group IIB element Selenide-based phosphor material to convert some of the original light emitted s from a light source of the device to a longer wavelength light to change the optical spectrum the output light. Thus, the device and method can be used to produce white color light. The Group IIB element Selenide-based phosphor material is included in a wavelength-shifting region optically coupled to the light source, which may be a blue-green light emitting diode (LED) die.
    Type: Application
    Filed: January 21, 2004
    Publication date: August 4, 2005
    Inventors: Janet Chua, Azlida Ahmad, Hwai Choo, Hisham Menkara, Christopher Summers
  • Publication number: 20050156510
    Abstract: A device and method for emitting output light utilizes a mixture of Group IIB element Selenide-based phosphor material and Group IIA element Gallium Sulfide-based phosphor material in which the Group IIA element includes Calcium, Strontium and/or Barium to convert some of the original light emitted from a light source of the device to longer wavelength light to change the optical spectrum the output light. Thus, the device and method can be used to produce white color light. The mixture of Group IIB element Selenide-based and Group IIA element Gallium Sulfide-based phosphor materials is included in a wavelength-shifting region optically coupled to the light source, which may be a blue light emitting diode (LED) die.
    Type: Application
    Filed: January 21, 2004
    Publication date: July 21, 2005
    Inventors: Janet Chua, Azlida Ahmad, Hwai Choo, Hisham Menkara, Christopher Summers